【Abstract】Background: T-cell death associated gene 8 (TDAG8) is a novel G protein-coupled receptor. It modulates many kinds of signal pathway and participates in a lot of pathophysiology process. Purpose: To review the research progress of TDAG8 about its characteristic properties, its downstream signal pathway, and its mainly functions. Content: TDAG8 belongs to seven transmembrane helix G protein-coupled receptor and it takes on proton-sensing and lipid-sensitive properties. Selective expression of TDAG8 was shown in lymphoid tissues, including peripheral blood leukocytes, spleen, thymus and lymph nodes, tumor cells, spinal cords, dorsal root ganglion, hypothalamus, amygdala, hippocampus, frontal cortex and striatum. It modulates PKA, PKC and RhoA signal pathways, and involves in regulation of tumor, immune response and pain. Trend: For the present, the research about TDAG8 is very superficial. With the development of the research, a lot of pathophysiology process of TDAG8 will be clearly elucidated.